Quantitative Relationship Between Coronary Calcium Score and Hyperaemic Myocardial Blood Flow As Assessed by Hybrid [15o]pet/ct Imaging in Patients Evaluated for Coronary Artery Disease

3 Objectives The aim of this study was to evaluate the relationship between CAC content and hyperemic myocardial blood flow (MBF) in patients undergoing hybrid [15O]PET/CT imaging. Methods We evaluated 249 (mean age 57 ± 10, 128 men) patients with a low to intermediate likelihood for coronary artery disease (CAD) and without a documented history of CAD undergoing vasodilator stress [15O]H2O PET/CT and CAC scoring. The CAC score and hyperemic MBF were analyzed. Results 97 of 249 patients (39%) had a CAC score (CACS) of zero. Of those with CAC, the CACS was 0.1-99.9, 100-399.9 and ≥ or = 400 in 33%, 18% and 10% of patients, respectively. Global CAC score showed a significant inverse correlation with hyperemic MBF (r = -0.30, p Conclusions A greater CAC burden is associated with a decreased hyperemic MBF. However, the strength of this association attenuated after adjusting for age, BMI and conventional risk factors, suggesting that CAC score does not add incremental value regarding hyperemic MBF. Our study also showed that in a symptomatic population with multiple CAD risk factor, MBF heterogeneity is not increased with increasing CAC content